"multi-filtering" indexpage lists and flexinode search integration

I have a requirement for my client to "drill down" into a large list of content (a "business directory" flexinode type, which has a few categories applied - such as state, business type) so I modified indexpage to do the following:

- admin/settings controlled "multi-filtering" aspect, where clicking on a category term shows a list of content matching that term (as usual), THEN underneath it renders the category lists / alphabetical list again.
- the user can click on another category term and it will build up a url such as "indexpage/flexinode-4/41,69" - the selection is currently an AND style of searching, but could be changed to use OR as well.

so, I can "drill down" to answer queries like this:

"show me all business directory entries with the NSW state and the RESTAURANT type"

voila! client happy.

I've attached my module for people to look at
- I've refactored quite a bit of the code
- linked into flexinode's search code (and refactored that module too) to have a search form on the indexpage. see comments starting with 'SM' to find the changes (added flexinode_search_form and flexinode_table)
- various SQL fixes (it's commented)
- the taxonomy terms are sorted alphabetically (I have a large flat category tree to render, so alphabetically allows the user to quickly find a term with their eye)
- probably a few other bits and bobs that's I've since forgotten about :)

Hopefully someone will be inspired by my code changes!

cheers,
SM